%general-entities; ]> $LastChangedBy$ $Date$ Open<acronym>SSH</acronym>-&openssh-version; Introduction to <application>Open<acronym>SSH</acronym></application> The OpenSSH package contains ssh clients and the sshd daemon. This is useful for encrypting authentication and subsequent traffic over a network. Package information Download (HTTP): Download (FTP): Download size: &openssh-size; Estimated Disk space required: &openssh-buildsize; Estimated build time: &openssh-time; <application>Open<acronym>SSH</acronym></application> dependencies Required Optional , , X ( or ), or , , and OpenSC Installation of <application>Open<acronym>SSH</acronym></application> OpenSSH runs as two processes when connecting to other computers. The first process is a privileged process and controls the issuance of privileges as necessary. The second process communicates with the network. Additional installation steps are necessary to set up the proper environment, which are performed by the following commands: mkdir /var/empty && chown root:sys /var/empty && groupadd sshd && useradd -c 'sshd privsep' -d /var/empty -g sshd -s /bin/false sshd OpenSSH is very sensitive to changes in the linked OpenSSL libraries. If you recompile OpenSSL, OpenSSH may fail to startup. An alternative is to link against the static OpenSSL library. To link against the static library, execute the following command: sed -i "s:-lcrypto:/usr/lib/libcrypto.a:g" configure Install OpenSSH by running the following commands: ./configure --prefix=/usr --sysconfdir=/etc/ssh \ --libexecdir=/usr/sbin --with-md5-passwords && make && make install Command explanations --sysconfdir=/etc/ssh: This prevents the configuration files from going to /usr/etc. --with-md5-passwords: This is required if you made the changes recommended by the shadowpasswd_plus LFS hint on your SSH server when you installed the Shadow Password Suite or if you access a SSH server that authenticates by user passwords encrypted with md5. --libexecdir=/usr/sbin: OpenSSH installs programs called by programs in /usr/libexec. sftp-server is a sshd utility and ssh-askpass is a ssh-add utility that is installed as a link to X11-ssh-askpass. Both of these should go in /usr/sbin not /usr/libexec. Configuring <application>Open<acronym>SSH</acronym></application> Config files /etc/ssh/ssh_config and /etc/ssh/sshd_config There are no required changes to either of these files. However, you may wish to view them to make changes for appropriate security to your system. Configuration information can be found in the man pages for sshd, ssh and ssh-agent sshd init.d script To start the SSH server at system boot, install the /etc/rc.d/init.d/sshd init script included in the package. make install-sshd Contents The OpenSSH package contains ssh, sshd, ssh-agent, ssh-add, sftp, scp, ssh-keygen, sftp-server and ssh-keyscan. Description ssh The basic rlogin/rsh-like client program. sshd The daemon that listens for ssh login requests. ssh-agent An authentication agent that can store private keys. ssh-add Tool which adds keys to the ssh-agent. sftp FTP-like program that works over SSH1 and SSH2 protocols. scp File copy program that acts like rcp. ssh-keygen Key generation tool. sftp-server SFTP server subsystem. ssh-keyscan Utility for gathering public host keys from a number of hosts.